AMD's six-core Phenom II X6 CPUs will underclock three cores and automatically overclock the other three

More details have emerged about how AMD's forthcoming six-core desktop CPUs, the Phenom II X6 lineup (a.k.a. Thuban), plan to handle all that processing power when most applications still can't make use of four cores.

The chip company has devised what it calls Turbo Core technology, which will overclock the remaining cores by 400MHz to 500MHz when it detects that three or more are idle. In order to get that boost, the idle cores will be reduced to just 800MHz (from 2.6GHz-3.2GHz, depending on the specific processor, according to AnandTech). If those cores aren't idle, the six cores will operate at their standard frequencies. Turbo Core is designed to keep the processor running within its thermal design power limits (125 watts or 95 watts, depending on the processor). Turbo Core is AMD's answer to Intel's Turbo Boost, which offers a somewhat different solution for providing auto-overclocking when it's needed most.

Current AM3 and AM2+ motherboards will support these new CPUs, though they may need a BIOS update. We still don't know basics like pricing and availability (though the end of April is a rumored date) for the Phenom II X6 parts, though they'll probably cost far less than Intel's $999 hexa-core Core i7 980X Extreme Edition. Whether they'll perform as well with features like Turbo Core will be the subject of much scrutiny from Intel and AMD fanboys alike.